the wheels of the Stingray robot. Subsequently, we had to
fabricate our own crank arm and pulley assembly for these
motors. To do this, we purchased some angled aluminum,
a cable clamp set (Figure 5), and patio door wheels
(Figure 6) at a local home improvement store.
To create the crank arms, we started by cutting the
angled aluminum to a usable size (roughly 12 inches). We
then placed the horseshoe bolt from the clamp set onto
the crank arm and marked where the two holes would go.
We used a spring punch to create start points for the drill
(Figure 7). After drilling the two holes, the horseshoe bolt
is placed around the motor shaft (Figure 8A), the bolts are
affixed to the other side, and tightened down (Figure 8B).
Make sure the flatted part of the motor shaft lays flush
against the aluminum bar to ensure the crank arm doesn’t
slip (Figure 9).
Next, we drilled a series of holes in the angled
aluminum crank arm so we could select different travel
distances for the anchor point. We
then attached one of the patio door
wheels to the end of the aluminum
crank arm (Figures 10A and 10B).
Holes were drilled in the edge of the
wheel to create points to which we
could affix the strings (Figure 11).
Once we had both of the
completed gearhead motor/crank
shaft assemblies built, they were
mounted with hose clamps to the
tops of the stands holding the
skeletons (Figures 12A and 12B).
You’ve Gotta Dance
The completed Trio de los
Muertos works better than we could
58 September 2014
Tamiya Gearbox with Crank
Suggested Gearhead Motors
Marlin P Jones
Video of the Trio de los Muertes Dancing
The Adventures of Marcos the Wise